Step 1: Gather Materials
Arduino project that needs to be remote controlled
IR receiver (easily attained from any old device that accepts input from IR remotes)
IR remote (pretty much any remote works, some may have issues in coding though)
The chassis I used is driven by 2 Tetrix CR Servos with K'Nex wheels Jury-rigged on, and is controlled by an Arduino Uno with a WingShield and an Adafruit MotorShield.
The IR receiver that I used is from an old USB TV remote adaptor that stopped working and had no use. It took me 10 minutes to take it all apart and extract all components.
The IR remote that I used was a handy-dandy little Car MP3 remote. If you want this remote, you can buy the remote with the player here. You can also extract the IR receiver from the MP3 player if you need to.